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Constant Pressure Valve

Constant Pressure Valve
UFSP-C type (PAT.)

Excellent pressure control and complete liquid shutoff performance

With over-discharge cutoff function

In addition to the same pressure regulating function as the Constant Pressure Valve UFSP type, this valve also performs a flow rate regulating function that not only cuts the over-discharge above the set flow rate but also maintains the set flow rate, allowing effective use of water resources and comprehensive flow rate control of the water distribution system.

The unique closure mechanism realizes complete water shutoff performance. The set outlet pressure is maintained even in the fully closed condition, therefore costs for pipes on the downstream side of the valve can be reduced.

The pilot valve does not have any minute, fixed restriction passage like a needle valve, and is therefore clog-resistant.
And, even if clogging by foreign material occurs, the built-in self-cleaning mechanism causes the clogged valve part to open automatically to remove the foreign material.

Due to its simple construction, troublesome adjustments are unnecessary. Being excellent in durability and practically maintenance-free, using this valve reduces maintenance costs.

Constant Pressure Valve

Patented in Japan, U.S.A., other



Rated pressure



Pilot A valve and pilot B valve respond to fluctuation of outlet pressure P2 to automatically adjust the main valve opening and maintain the outlet pressure at the set pressure.
Also, an orifice is provided at the inlet side of the valve, and the set flow rate is maintained by operation of pilot C valve driven by differential pressure (P1-P1') that arises between the front and the rear of the orifice due to the flow rate fluctuation.


During water supply, pilot A valve and pilot B valve operate in the same manner as in the Constant Pressure Valve to form intermediate pressure Pe, which is transmitted to the top of the main valve for automatic adjustment of the main valve opening. When the set flow rate is exceeded, pilot C valve is closed by differential pressure (P1-P1'), causing intermediate pressure Pe to rise and restricting the main valve opening to prevent over-discharge.


The set flow rate can be finely adjusted with the flow rate adjustment coil spring of the pilot valve. If flow rate control over a wide range is required, a butterfly valve or other flow rate adjustment valve (optional) may be installed in place of the fixed orifice.


Inlet pressure (Primary pressure)
Max. 1MPa (For JIS 10K standard)

Outlet pressure (Secondary pressure)
50kPa or more

Set pressure adjustment range
+/- 70kPa

Operating differential pressure
0.1MPa or more

Flow rate characteristics when the opening of the butterfly valve (installed in place of the inlet side orifice) is adjusted

Water shutoff performance when the downstream side terminal valve is fully closed
Constant Pressure Valve /  Flow rate characteristics
Constant Pressure Valve /  Water shutoff performance

Selection chart/Outer dimensions

Please refer to Common specifications & Outer dimensions.

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